michell



Fb. s 1924. Re. 15,756

A. G. M. MICHELL MECHANISM FOR THE INTEHCONVERSION OF RECIPROCATING AND ROTARY MOTION Original Filed June 11, 1918 :s heets-sheet 1 INVENTOR ANTHONY 6. M M/Cl/fLL Feb. 5, 1924. I

V A. G. M. MICHELL MECHANISM FOR THE INTERCONVERSION OF RECIPROCATING AND ROTARY MOTION I5 Sheets-Sheet 2 Original Filed June 11. 1918 IJVIIIIIIII "5)! INVENTOR ANTHONY a. M. M/ c HELL ATTORNEY Feb. 5 1924.

A. G. M. MICHELL MECHANISM FOR THE INTERCONVERSION 0F RECIPROCATING AND ROTARY MOTION Original Filed June 11. 1918 3 Sheets-Sheet 5 INVENTOR ANTHONY 6. M MIC/IELL 6% ATTORNEY ll other heat englnes, compressors iieiaued Feb. 5, 1924.

UNITED STATES PATE NT'OFFICE.

. ANTHONY GEORGE KALDON KICHELL, OF MELBOURNE, VICTORIA, AUSTRALIA, AS

SIGNOB TO CRANKLESS (AUS) PROPRIETARY LIMITED, OF MELBOURNE,

VICTORIA, AUSTRALIA- HECHANISI FOR THE INTEBCONVEBSION OF RECIPBOCATING AND ROTARY MOTION.

Original application flied June-l1, 1918, Serial No. 239,384 Bgncwed April 28, 1921, Serial 1T0. 465,243. riginal ll'o. 1,,057, dated larch "I, 1922. Application for reissue illell October 81, 1928. Serial Australia, have invented certain new and useful Improvements inMechanism for the acting piston;

Interconversion of Reciprocating and Rotary Motion, of which the following is a specification.

The object of this invention is an improved means of obtaining harmonic reciprocating motion from uniform rotary motion or vice versa, applicable to steam and for air and gas, and pumps, as well as to other machines in whi h the interconversion of these two types of motion is required.

Theinvention consists essentially in the N combination of a reciprocating element or elements, with a rotating ,drive plate, or swash plate, and one or: more slipperso special construction as hereinafter described forming connecting elements be can the ll said reciprocating and rotary elements. 7

The em/plo ment of a swash plate or drive plate in mec anism for the purpose stated is'well known and it has been customary to employ wheels or rollers to make contact so with a. minimum of friction between the recilprocating element and the drive plate.

1 ore recently ball races have been emplo ed for effecting the connection stated an it has also been proposed to use .slide blocks as having plane surfaces making lubricated contact with the drive plate and rotating about axes parallel to the line of motion of the reciprocating element. Suchdevices, however, have not proved suitable for op eration with intense pressures and high speeds, and conse uently although mechanism of this class as beensuccessfully employed for the operation of hydraulic pumps and motors, it has not hitherto been suitable w for use in conjunction with engines and drive plate and the slippers in another po- ,chambers 6, 6 of the cylinders being between accompanying drawingsillustrate a p practical and the preferred form of drive plate mechanism according to this invention and its application to a reciprocating en no. r v

igs. 1, 2-and 3 illustrate the essential parts of the invention as applied to double- Fig. 1 being a longitudinal. section through a cylinder and its piston parallel to the axis of rotation of thedrive plate;

Fig. 2 a detail showing portion of the sition; and

Fig. 3 a plan view of one of the slippers;

Figs,.4, 5, 6, 7 and 8 illustrate one method of application of the invention to'a complete machine, viz: a self-contained steamdriven air compressor, Figs. 4 and 6 being axial sections respectively on the lines 4-4 and 6-45, of'Fig. 7, Fig. 5' an enlarged detail, Fig. 7 a cross-section on the line 7-7 of Figs. 4 and 6 with partsvremoved; and

Fig. 8- a, detail viewshowing alternative constructions.

In Fig. 1 the drive plate 1 is shown mounted obliquely on the rotating shaft 2 which revolves in the bearings 3, 3 indicated by dotted lines. One of the working cylinders 4, 4 of an engine or compressor, whose axis is parallel to that of the shaft 2, is

the double-ended piston 5, 5, the working the ed in any usual manner suitable for the fluid with which it is to operate. The two ends ofthe double piston are rigidly connected together by the central bar '8 which may have a projection 9 moving-in a slot 10 outside ends of the double piston 5, 5 and the closed ends (not shown) of the cyln and revolves with the shaft 2. The dou le-ended piston 5, 5 is constructformed either in the central portion of the double cylinder 6, 6 as shown, or inthe frame of the engine so as to prevent the piston from rotating while allowing it to reciprocate parallel to its axis.

In order to transmit motion from the drive plate 1 to the pistons 5, 5 or vice versa, two slipper blocks 11, 12 are arranged one on each side of the drive plate 1 as shown havin plane working surfaces adapted to make ubricated contact with the corresponding plane surfaces 7, 7 of the drive plate, and in order to enable the slippers 11, 12 to follow the varyin direction of inclination of the latter sur aces to the axis of the piston as the drive plate rotates, they are furnished with universal joints connecting them to the piston 5, 5. The universal joints may convenient-1y take the form of spherical bosses 13, 14 uponthe slippers 11, 12, such bosses fitting into hollow spherical seats in the cups 15, 16 secured to the piston 5, 5. In Fig. 1 the drive plate 1 and slippers 11, 12 are, shown in such a position that the normal lines to their plane working surfaces have the maximum obliquity to the plane of the drawing. In Fig. 2 a portion of the periphery of the drive plate 1 and the slippers 11, 12 are shown in the position corresponding to rotation through 90 from the position shown in Fi 1, the normal lines to the working sur aces being then turned into the plane of the drawing. In

'- order to adjust the working clearance which is necessar to allow eflicient lubrication without un ue 12 and the working faces 7, 7 of the drive late 1, the cups 15, 16 are constructed with he threads and screwed into the pistons 5, 5, the adjustment being made permanent b means of set screws 17, 18 engaging with the peripheral notches 17 and 18 in the en the drive plate 1 revolvesdnvariably or usually-in one direction, the slippers 11,

' 12 are preferably made as shown in Fig. 3

with their bosses 13, 14 slightly behind the centres of the plane workin surfaces of the slippers. The slippers wil then operate so as to allow wedge-shaped films of lubricant to be formed between their working surfaces and those of the. drive plate in a manner which is now well understood. For

the same put so these sli pers ll, 12 are also preferab y constructed withrelatively weak or flexible on both the lea ing and trailing sides of the plate portions which make contact with the drive plate. In order to prevent the axis of the piston 5, 5 as the revolves, the latter may'be furnished with a slippers 11, 12 tom revolvingabout the ve plate 1 projectin eccentric guide ring 19 shaped so as to t approximately the inner edge 20 of the slipper 11, a similar guide ring beplay between the slippers 11,

rtions on the leading'or I 15,-rue

ing formed on the opposite side of the drive plate 1 to form a similar guide for the slipper 12.

Alternatively to the construction of the slippers with spherical bosses fitting in concave seats attached to the pistons as above described, the pistons may be fitted with spherical projections fitting in concave seats in the slippers. Or the slippers andpistons may be connected by universal joints of other suitabletypes as, for instance, with the well known Hookes or Cardans joints, the essential purpose being to allow the slippers to change the incllnation of their working faces in every direction while maintaining the perpendicular distance between those working faces constant, or approximately constant.

In the example of the application of the, invention illustrated in Figs. 4, 5, 6 and 7,

by a central bar 8 is arranged substantially as already described in connection with Figs. 1.and 2. The steam and air ends. of the double piston are shownin the drawings of equal diameters but may be of different diameters adapted to the working pressures of the two fluids. Each double piston is provided with slipper blocks 11, 12 as already described, makin working contact with a drive late 1 rigi ly mounted on the shaft 2 which extends through the whole length of the combined machine befiig mounted in bearings 21, 22.

The drive plate 1 is preferably constructed with a cylindrical boss 1, integral with a plate portion having the form of an oblique slice of a cylinder, and thrust rings 21322 are interposed between the boss 1 and the bearings 21 and 22 to take any'unbalanced axial force acting on the drive plate.

Air enters the compressor .cylinder 6during the forward movement of'the piston 5 throu h the open end 23 of the end cover 24 being admitted through the port 25 of the rotating valve 26 mounted on the shaft 2 when silch portrcgisters with either of thefour admision ports 27 in the late 28 which covers the otherwise open en 5 of the .air cylinders 6'. On the return strokes of the pistons .5, compressed air is. delivered,

approximately fittingthe ports 27.

ports 27 and the port 30 :1

ve- 26 into the annular flow principle and ing 32, and may jacket 33, for cooling purposes.

The cylinders 6 may formed as liners, as shown, being inserted in the common cas- A similar casing 32, which may be bolted to the casing 32 .as shown, on the line 7-1-7 contains the steam cylinders 6, also formed as liners. The steam ends of these cylinders are controlled by a rotating valve 34 having an admission port 35 which registers in sue cession with the four admission ports 36 in the plate 37 covering the otherwise open ends of the cylinders 6. Steam, supplied through the pipe branch38 (Fig. 6) is-admitted through the ports 35 and 36 from the chamber 38 in the end cover 39. The steam cylinders illustrated are arranged on the unithe exhaust from each cylinder takes place through a ring of ports 40 into an annular exhaust steam chamber 41 formed in the casing 32 and connected the casings 32 and 32 and is with the exhaust branch 42 (Figs. 6 and 7) Thedri-ve plate 1 is enclosed in a central chamber 43 formed by the open inner ends of provided with means for forced lubrication from the oil pump 44 (Fig. 7) which delivers jets of oil through the passages, 4545, bearing chamthe pump ber 43 (Figs. 6 and 7) driven througha spindle 48 and gear wheels 49, 50 from a pinion in Fig. 1. As shown in shaft 2. from rotating about their axial centre-lines the 'means' shown in Fig. 5 may be employed as alternatives to the projection 9 on the bar 8, and rings 19 on drive plate 1, as shown v Figs. 4 and 5 rotation of the pistons bar 8 which consists of the bridge portion of the oke piece 52 to whichare screwed the sai pistons 5, 5"; and the cups 15, and the bar 8 is slotted at 53 so as to be guided longitudinally by the stud piece 54 fixed to the casing 32, and engaging with the slot 53.

A ball-ended projection 55 from the slipper 11, also engages with the slot 53, and the slipper 11 is thus prevented from revolvin though free to oscillate a-ccordin to the varying direction of inclination 0 its surface to contact with the plate 1.

An engine constructed as herein described, witheither three, four (as shown), or any greater number of istons spaced equid stantly around the circumference of the drive plate, admits of perfect dynamic balance in all directions so as to communicate no vibration to its foundation, provided that the be surrounded by a water 47 agamstthe centralsuction branch 45, on

51 mounted on the main In order to prevent the slippers 11 5, 5 is restrained by the asses of'the drive plate and reciprocating pistons are correctly adjusted. For this pur pose it is necessary that all the. pistons, if

equidistant, from the axis, shall be of equal mass, and that the mass of that portion of the drive plate outside the boss which portion may be regarded as an oblique slice of a cylinder is determined by the algebraical formula e in which M is the mass of the drive plate; 11 the number and m the mass of each of the pistons with its attachment; R the radius of the outer surface of the drive plate measurednormally to the axisgm the radius of the boss of the drive plate; and A the distance between the axis of the drive plate and that of one of the pistons. The boss in this formula is the axiallysymmetrical part of the drive late, or the dynamically balanced part t formula is concerned may be an inte ral' part of thedrive plate as shown, or of the shaft,

or may be the shaft itself. The rotary valves, and other rotating parts, are independently balanced in the usual manner.

It is to be understood that the invention is not limited to the use of one or more double-ended pistons as described above, butthat the construction which is the essence of the invention can be employed with a single-ended piston and .one slipper, or with a single-ended piston having an extension to the opposite 'side of the'drive platefrom the piston for the purpose of carrying a second slipper. These constructions are illustrated in Fig. 8 in which the single slipper 11 coacting III A yoke piece 58 attached to the cylinder 57 is slotted to receive the ball 55, attached to the slipper and stud 54 attached to the casing 32 as already described. In order to assist the piston 56 in making its return stroke a compression spring 59 ma be inserted between it and the closed end 60 of the cylin- Y der 57. In certain cases the sprin 59 may be omitted the return motion of the piston being actuated either by the pressure of the Working fluid or by the adhesion of the oil-film between the slipper 11 and drive ,.plate. 1. In the latter case the slipper must be ositively attached I to the piston by a ookes or Cardan joint as hereinbefore indicated.

It will also be understood that for special purposes the essential features of the invention may be applied to a swash plate having two plane, but not parallel,- working faces 1n conjunction wit-h single-ended pis-v tons as above described in connection with Fig. 8 of which one or'more are fitted .with slippers co-acting with one working inter"??- 12 (also dotted in Fig.) 8) on the opposite,

while another or others co-act with the other 'working face'of 'the swash plate. By this means the single-acting pistons on one. side of the drive plate have working strokes of a certain length, while the strokes ofthose on the other side have a different length- By an alternative arrangement, the spring 59 being omitted, the yoke piece 58 ma be extended, as shown in dotted lines in 1g. 8 and arranged to carrya second slipper side ofthe drive plate 1, the action of the two slippers being then precisely as already described connection with Figs. 4, 5, 6 and 7.

Itwill further be understood that the details of construction may be modified for f the use of the mechanism as in conjunction with a steam or internal combustion engine, pump, or compressor whether double-actmg or single-acting], instead of as a com-' -b1ned engine and compressor as above described. For uses in conjunction with these .machines other than those last mentioned the shaft 2 would be extended outside the casing as'indicated at 2,"Figs. 4 and 6 and would be fitted with a coupling, ulley, or

the like b which the power deve oped by,' to, the drive plate 1, would be* or 'applie transmitted.

What I claim is: I 1.. In mechanism of the character described, the combination of a. swash plate, a

reciprocable element, and a slipper of the I with a working face of the swash plate, the

slipper being non-rotatable about an axis parallel to the direction of movement of the reciprocable element, a universal joint connecting the'slipper with the reciprocable element, and means for maintaining the slipper. in cooperative working relation with the working face of the swash plate.

comprising 3. Mechanism for the purpose stated,

a rotary swash plate having opposite tru y plane working faces disposed obliquely relatively to the.. axis of revolu tion of the swash plate, a reciprocable element, and, a pair of plane surfaced "slippers having articulated connections with said axis parallel-to the -direction of movement a a swash plate, reciprocable elements symreciprocable elements, andmeans-for preventing rotation of the slipper about an of the reciprocable element, said slippers bearing respectively on the opposite faces of the swash plate.

Fr 4. In mechanism for the purpose stated,

the combination with a ,swash' plate having two plane and parallel Working faces, of a reciprocable elementhaving a pair f opposed slippers having plane working faces cooperating with the respective working each. slipper being capable of articulated faces at opposite sides of the swash plate,

movement but 'non-rotatable-'relatively to the reciprocable direction of movement of the element while maintaining the perpendi-' cular distance between their working faces substantially constant.

. 5. Mechanism for the purpose stated con sisting of the combination with a swash plane surfaced slipper cooperative therewith, a reciprocable element, a universal joint 'connectlng the slipper to the. reciprocable element, and means for holding-said slipper from rotation relatively to the reciprocable element about an axis parallel to the direction of movement of said element.

7. In mechanism of the' character described, the combination with a swash plate,

a reciprocable element, a plane surfacedslipper cooperative with the swash plate and having an. articulated connection with said reciprocable element, and me'ansfor restraining rotation of the slipper element relatively to the reciprocable element but permitting reciprocation. of the latter.

. 8.'In mechanism for the purposestated, a casin shaft of the latter and jets directed-toward containing the swash plate with means including .a pump dr'rvenfrom the a the swash plate for effecting forced feed lubrication to the working faces of the same. 9. In mechanism forthe purposestated,

in combination, a swash plate, 'a reciproca;

ble element comprising a piston carrying a slipper element articularly connected thereto at a point offset in rear of the leading end of the slipper element to produce an interposed wedge-shaped lubricant 'film connection between said plate and the slipper element and means for projecting a lubricant against the working face of the swash plate.

10. In mechanism for .the purpose stated,

metrically balanced about a swash late having truly plane working faces, sai elements comprising pistons each carrying an cated contact with said working surfaces,

' table with the shaft having said pistons and slippers being restrained from rotation, and means driven from the shaft of said plate for effecting forced lubrication to said working faces.

11. Mechanism of the character described comprising a swash late, reciprocable-elements disposed wit angular symmetry about said plate and arranged to eifect dynamic balance therewith and a connectin slipper between each of said elements an the swash plate, each of said slippers having an articulated connection with its reciprocable element.

12. Mechanism of the character described comprising a rotary shaft, a member rotaa working surface oblique to the axis of rotation thereof thereby being out of dynamic balance, at least three elements reciprocable in paths substantially parallel with the axis of the shaft disposed with angular symmetr about the shaft, said elements being of such mass and so ositioned as to counteract the unbalance 0 said member, and operative connections between the member and said elements. V

13. Mechanism of the character described comprisinga shaft, 'a drive plate thereon, at

least a part of said drive plate-being in the form of an obli ue slice of a cylinder and out of d amic alance, a pluralit of elements 0 ual mass reciprocable 1n paths parallel with the axis of the shaft equidistant from said axis,disposed with angular symmetry, about the shaft, and operative connections between the drive plate and said. elements, the various parts of said combination being characterized by the proportions the shaft, R is the radius from the axis of the shaft to the periphery of the drive plate normal to said'axis, and r is the radius of the shaft or of the dynamically balanced part of the drive plate.

V ANTHONY GEORGE MAI-DON IICHELL 

